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Date: Thu, 22 Jul 2004 20:14:26 +0200
From: Ingo Molnar <mingo@elte.hu>
To: linux-kernel@vger.kernel.org
Cc: Rudo Thomas <rudo@matfyz.cz>, Matt Heler <lkml@lpbproductions.com>
Subject: Re: voluntary-preempt I0: sluggish feel
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* Ingo Molnar <mingo@elte.hu> wrote:

> > > Oh, sorry for the noise. It was the NVIDIA driver. The open one works
> > > much better with the I0 patch.
> > 
> > i can reproduce this and i dont have the NVIDIA driver. When logging
> > in over the network then shell output is chunky with a setting of 2
> > (softirq redirection), shell output is smooth with a value of 1.
> 
> found the reason: ksoftirqd runs at priority 19 by default and this
> causes batching and some softirq starvation. Does the sluggishness go
> away if you do 'renice -10 2' [where '2' is the PID of ksoftirqd]?

i've uploaded -I1 which does this automatically:

  http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.8-rc2-I1

	Ingo